1. Field of the Invention
The present invention relates to a reel braking device for use in VTRs (video tape recorders), etc., and to a recording and/or reproducing apparatus, such as a VTR, provided with the reel braking device.
2. Description of Related Art
In the field of VTRs, for example, there has been heretofore known a reel braking device which constitutes a one-way clutch for a reel mount on which a reel is mounted, as illustrated in FIGS. 5(a) and 5(b) and FIG. 6.
Referring to FIGS. 5(a) and 5(b) and FIG. 6, a brake lever 53 is rotatably supported by a shaft 52 vertically provided on a chassis 51, and a sub-lever 54 is provided to be rotatable about a shaft 53a on the brake lever 53. The sub-lever 54 is urged to rotate in the counterclockwise direction about the shaft 53a by a spring 55 which is interposed between the sub-lever 54 and the brake lever 53. Then, the sub-lever 54 is able to be in abutting contact with a cylindrical portion (surface) 56a of an outer periphery of a reel mount 56 rotatably installed on the chassis 51, and a pawl portion 53b of the brake lever 53 is engageable with a gear portion 56b of the reel mount 56.
In the above construction, as shown in FIG. 5(a), when the reel mount 56 is rotated in the direction of an arrow "a", the sub-lever 54 is driven to turn in the direction of an arrow "c" due to friction produced between itself and the cylindrical portion 56a, causing the brake lever 53 to rotate in the direction of an arrow "e". This brings the pawl portion 53b of the brake lever 53 into engagement with the gear portion 56b of the reel mount 56, so that the gear portion 56b stops rotation and is kept fixed.
Conversely, as shown in FIG. 5(b), when the reel mount 56 is rotated in the direction of an arrow "b", the sub-lever 54 is driven to turn in the direction of an arrow "d", causing the brake lever 53 to rotate in the direction of an arrow "f". This makes the pawl portion 53b to be disengaged from the gear portion 56b, so that the gear portion 56b is free to rotate. Incidentally, the brake lever 53 is stopped by abutting on a stopper 57 disposed on the chassis 51.
The conventional reel braking device described above, however, requires at least three parts, i.e., the brake lever 53, the sub-lever 54 and the spring 55. Therefore, the conventional reel braking device has had problems that the number of parts is large, the efficiency of assembly is poor, and the cost is high.
It may be conceivable that the sub-lever 54 is formed integrally with the brake lever 53 by simultaneous molding, while the sub-lever 54 is given resiliency enough to hold it always in pressure contact with the cylindrical portion 56a of the reel mount 56. However, such a construction accompanies problems in that, because the lever has to develop resiliency in itself, selection of appropriate molding materials is subject to limitations and the resiliency cannot be always held constant because of molding error or secular variation. Thus, the braking operation would tend to become unstable.